If you change the mountPoint, it will not replace your current weapon - it sees your last item (say, Wrench) in slot 0 (right hand) and other thing in slot 1 (left hand) - not replacing it. It also won't fire unless you use Armor::setImageTrigger(%obj,%slot,%trigger) in an event or servercmd. (I use other functions, serverside, to override jets and have it fire there.